Image sensor, image pickup apparatus, image sensor-identifying method, image forgery-preventing method, and image alternation-limiting method

ABSTRACT

An image sensor  30  includes an image information processing unit  4  that forms integrated information in which image sensor identification information capable of identifying the image sensor  30  and image information obtained by an analog/digital conversion unit  25  are associated with each other, and an image information output unit  24  that outputs the integrated information to an external unit.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 16/859,473, filed on Apr. 27, 2020, which is acontinuation application of U.S. patent application Ser. No. 16/086,524,filed Sep. 19, 2018 (now U.S. Pat. No. 10,764,492 issued on Sep. 1,2020), which is a U.S. National Phase of International PatentApplication No. PCT/JP2016/088895 filed on Dec. 27, 2016, which claimspriority benefit of Japanese Patent Application No. JP 2016-073266 filedin the Japan Patent Office on Mar. 31, 2016. Each of theabove-referenced applications is hereby incorporated herein by referencein its entirety.

TECHNICAL FIELD

The present technology relates to an image sensor, an image pickupapparatus, an image sensor-identifying method, an imageforgery-preventing method, and an image alternation-limiting method.More particularly, the present technology relates to a technology of animage sensor that outputs identification information specific to theimage sensor and image information acquired by that image sensor inassociation with each other.

BACKGROUND ART

In recent years, for example, a complementary metal oxide semiconductor(CMOS) image sensor, a charge coupled device (CCD) image sensor, or thelike is used as an image pickup element (image sensor) of asemiconductor that converts light entering from a lens of an industrialapparatus such as a portable terminal and a digital camera intoelectrical signals. As an image pickup apparatus having a function ofgenerating image information by using such an image sensor, there isknown one capable of mounting a plurality of recording media for thepurpose of generating backup data, for example.

In order to guarantee consistency of data recorded on the plurality ofrecording media, Patent Literature 1 has proposed, for example, an imagepickup apparatus including a processing means that performs processingon at least one of first data recorded on a first recording medium orsecond data recorded on a second recording medium and a determinationmeans that determines whether or not the first data has particularrelevance to the second data, in which the processing means determineswhether or not to allow the processing on the basis of a determinationresult of the determination means.

CITATION LIST Patent Literature

-   Patent Literature 1: Japanese Patent Application Laid-open No.    2005-176263

DISCLOSURE OF INVENTION Technical Problem

However, Patent Literature 1 has disclosed a technology of guaranteeingconsistency between a plurality of pieces of data, but Patent Literature1 has not disclosed a technology of identifying, on the basis ofacquired image information, an image pickup element which has generatedthat image information.

Therefore, with the technology of Patent Literature 1, it is difficultto identify the image pickup element which has generated the imageinformation. There is a problem that it is impossible to guaranteeconsistency between acquired image information and picked-up imageinformation.

The present technology has been made in view of the above-mentionedcircumstances and it is an object thereof to provide an image sensorcapable of guaranteeing consistency between acquired image informationand picked-up image information.

Solution to Problem

In order to solve the above-mentioned problem, an image sensor that isan example of the present technology at least includes: an imageinformation processing unit that forms integrated information in whichimage sensor identification information capable of identifying the imagesensor and image information obtained by an analog/digital conversionunit are associated with each other; and an image information outputunit that outputs the integrated information to an external unit.

Further, an image pickup apparatus that is an example of the presenttechnology at least includes: an image sensor including an imageinformation processing unit that forms integrated information in whichimage sensor identification information capable of identifying the imagesensor and image information obtained by an analog/digital conversionunit are associated with each other, and an image information outputunit that outputs the integrated information to an external unit.

Further, an image sensor-identifying method that is an example of thepresent technology includes identifying an image sensor by analyzingintegrated information in which image sensor identification informationcapable of identifying the image sensor and image information obtainedby an analog/digital conversion unit are associated with each other, theintegrated information being output from the image sensor to an externalunit.

Further, an image forgery-preventing method that is an example of thepresent technology includes preventing forgery of image information byusing electronic signature information in which image sensoridentification information capable of identifying an image sensor andimage information obtained by an analog/digital conversion unit areassociated with each other and are encrypted, the electronic signatureinformation being output from the image sensor to an external unit.

Further, an image alternation-limiting method that is an example of thepresent technology includes giving an image alternation privilege onlyto decrypted image information obtained by performing decryptionprocessing on image information including electronic signatureinformation in which image sensor identification information capable ofidentifying an image sensor and the image information obtained by ananalog/digital conversion unit are associated with each other and areencrypted, the image information being output from the image sensor toan external unit.

Advantageous Effects of Invention

In accordance with the present technology, it becomes possible toprovide an image sensor capable of guaranteeing consistency betweenacquired image information and picked-up image information. It should benoted that effects of the present technology are not necessarily limitedto the above-mentioned effects and any effect described in the presentdisclosure may be provided.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 A block diagram showing a configuration example of an imagepickup apparatus according to the present technology.

FIG. 2 A block diagram showing a first stacking example of an imagesensor according to the present technology.

FIG. 3 A block diagram showing a second stacking example of the imagesensor according to the present technology.

FIG. 4 A schematic view for describing a first imageinformation-outputting method according to the present technology.

FIG. 5 A schematic view for describing a second imageinformation-outputting method according to the present technology.

FIG. 6 A conceptual diagram for describing an image sensor-identifyingmethod according to the present technology.

FIG. 7 A flowchart for describing the image sensor-identifying methodaccording to the present technology.

FIG. 8 A conceptual diagram for describing a first imageforgery-preventing method according to the present technology.

FIG. 9 A flowchart for describing the first image forgery-preventingmethod according to the present technology.

FIG. 10 A conceptual diagram for describing a second imageforgery-preventing method according to the present technology.

FIG. 11A A flowchart for describing the second image forgery-preventingmethod according to the present technology.

FIG. 11B A flowchart for describing the second image forgery-preventingmethod according to the present technology

FIG. 12 A flowchart for describing an image alternation-limiting methodaccording to the present technology.

FIG. 13 A schematic view showing a configuration example of a personalcomputer according to the present technology.

MODE(S) FOR CARRYING OUT THE INVENTION

Hereinafter, favorable modes for carrying out the present technologywill be described with reference to the drawings. Note that embodimentsto be described below show examples of representative embodiments of thepresent technology, and the scope of the present technology should notbe interpreted narrowly due to those embodiments. Descriptions are givenin the following order.

1. Configuration Example of Image Pickup Apparatus 2. First StackingExample of Image Sensor 3. Second Stacking Example of Image Sensor 4.First Image Information-Outputting Method 5. Second ImageInformation-Outputting Method 6. Image Sensor-Identifying Method 7.First Image Forgery-Preventing Method 8. Second Image Forgery-PreventingMethod 9. Image Alternation-Limiting Method 10. Various GenerationMethods for Electronic Signature Information 11. Various EncryptionMethods for Electronic Signature Information

12. Various Reissue Methods for Electronic Signature Information afterDevelopment

13. Addition Method for Reliability Information 14. Application Service15. Configuration Example of Personal Computer

1. Configuration Example of Image Pickup Apparatus

FIG. 1 is a block diagram showing a configuration example of an imagepickup apparatus of an embodiment according to the present technology.An image pickup apparatus 1 is an apparatus that picks up and records animage and the like. The image pickup apparatus 1 includes, as anexample, a digital camera, a video camera, and the like. The imagepickup apparatus 1 includes a power supply circuit 2, an image pickuplens 3, an image information processing unit 4, a display processingunit 5, a display unit 6, a camera control unit 7, an image recordingcontrol unit 8, an image recording unit 9, and an image pickup element(image sensor) 10. As the image sensor, a complementary metal oxidesemiconductor (CMOS) image sensor, a charge coupled device (CCD) imagesensor, or the like can be used, for example. Note that the image pickupapparatus and the image sensor according to the present technology arenot limited to this embodiment.

The power supply circuit 2 supplies power to the image sensor 10 via apower supply line 11. The image pickup lens 3 concentrates object lightand guides it to the image sensor 10.

Under the camera control unit 7 via a signal line 12, the image sensor10 generates image information on the basis of light received throughthe image pickup lens 3. The image sensor 10 outputs the generated imageinformation to the image information processing unit 4 via the signalline 13.

The image information processing unit 4 executes image processing suchas demosaic processing and white balance processing on image informationacquired from the image sensor 10. The image information processing unit4 outputs the processed image information to the display processing unit5 and the image recording control unit 8 via a signal line 14.

It is assumed that the display processing unit 5 executes displayprocessing such as gamma correction processing, color correctionprocessing, and contrast adjustment processing on the acquired imageinformation in a manner that depends on needs. The display processingunit 5 outputs image information after the display processing to thedisplay unit 6 via a signal line 15. The display unit 6 displays theimage information received from the display processing unit 5.

The camera control unit 7 comprehensively controls the image pickupapparatus 1. In accordance with a user's operation, the camera controlunit 7 outputs a control signal to the image sensor 10 via a signal line16 for generating image information.

The image recording control unit 8 causes the image recording unit 9 torecord the image information from the image information processing unit4 via a signal line 17. The image recording unit 9 records the imageinformation.

2. First Stacking Example of Image Sensor

FIG. 2 is a block diagram showing a stacking example of a firstembodiment of a stacked image sensor according to the presenttechnology. For example, a stacked CMOS image sensor can be used as thestacked image sensor, though the present technology is not limitedthereto. Further, a backside illumination type CMOS image sensor can beused as the CMOS image sensor. In the backside illumination type CMOSimage sensor, pixels, circuits, and the like are formed on a siliconsubstrate, and the silicon substrate on the back side of the imagesensor is thinned to several micrometers to have a structure for takingin light.

As shown in FIG. 2, in a stacked image sensor 20 of this embodiment, asignal processing substrate 23 is arranged on the back side of a pixelsubstrate 22 including a sensor unit 21 that photoelectrically convertsoptical signals from an object into electrical signals. In this manner,it is stacked in two layers. The signal processing substrate 23 includesthe image information processing unit 4 as shown in FIG. 1 and an imageinformation output unit 24.

The image information processing unit 4 includes at least ananalog/digital conversion unit (A/D conversion unit) 25 that convertsthe electrical signals output from the sensor unit 21, which are analogsignals, into digital signals and an integrated-information forming unit26 that forms integrated information in which image information obtainedby the A/D conversion unit 25 and image sensor identificationinformation of the image sensor 20 are associated with each other.

Here, the “image sensor identification information” refers toinformation capable of identifying the image sensor, such as typeinformation of the image sensor, a manufacture number specific to theimage sensor, manufacture date and time information of the image sensor,GPS information, an image pickup condition including an image pickuptime, and the like.

The image information output unit 24 outputs image information outputfrom the A/D conversion unit 25 and integrated information output fromthe integrated-information forming unit 26 to the external unit.

Here, the “external unit” refers to a recording medium that saves imageinformation generated by the image sensor, a network that transmits thatimage information, an image pickup apparatus main body such as a digitalcamera that processes that image information, a personal computer (PC),a portable terminal, a game console, a contactless IC card such asFeliCa (registered trademark), a USB memory, and the like.

As in the image sensor 20 of this embodiment, by employing a two-layerstacking structure in which the signal processing substrate 23 iscovered with the pixel substrate 22, an arrangement is achieved toprevent the external unit to easily read and analyze the integratedinformation. Thus, the security for the integrated information can beincreased.

3. Second Stacking Example of Image Sensor

FIG. 3 is a block diagram showing a stacking example of a secondembodiment of the stacked image sensor according to the presenttechnology. As in FIG. 2, for example, the stacked CMOS image sensor canbe used as the stacked image sensor, though the present technology isnot limited thereto.

As shown in FIG. 3, in a stacked image sensor 30 of this embodiment, thesignal processing substrate 23 is arranged between the pixel substrate22 including the sensor unit 21 and a memory substrate 31. In thismanner, it is stacked in three layers. As in FIG. 2, the signalprocessing substrate 23 includes the image information processing unit 4and the image information output unit 24.

The memory substrate 31 includes the image recording control unit 8 thatcontrols recording of the image information output from the imageinformation processing unit 4 and the image recording unit 9 thatrecords the image information output from the image recording controlunit 8. In accordance with a command signal from the image informationprocessing unit 4, the image recording unit 9 outputs the recorded imageinformation to the image information processing unit 4.

As in the image sensor 30 of this embodiment, by employing thethree-layer stacking structure in which a front surface and a rearsurface of the signal processing substrate 23 are covered with the pixelsubstrate 22 and the memory substrate 31, an arrangement is achieved tofurther prevent the external unit to easily read and analyze theintegrated information in comparison with the two-layer stackingstructure as shown in FIG. 2. Thus, the security for the integratedinformation can be further increased.

4. First Image Information-Outputting Method

FIG. 4 is a schematic view for describing an imageinformation-outputting method of the first embodiment according to thepresent technology. This embodiment shows a mode to transmit the imageinformation and the integrated information from an image sensor to anexternal apparatus that is an example of the external unit via one imagetransmission path.

Image information 44 generated by the image sensor 30 of this embodimentis transmitted to an external apparatus 43 that is an example of theexternal unit through an image transmission path 42 via an interfaceunit as well as integrated information 45 in which the image information44 and the image sensor identification information of the image sensor30 are associated with each other. The external apparatus 43 includes anintegrated-information analyzing unit 46 that identifies the imagesensor 30 by analyzing the transmitted integrated information 45. Theexternal apparatus 43 receives the image information 44 and theintegrated information 45 in the integrated-information analyzing unit46, analyzes integrated information 56, and identifies the image sensor30.

The image sensor 30 is capable of writing the integrated information 45such as encrypted electronic signature information outside an effectiveimage frame of the image information 44 and outputting the imageinformation 44. With this configuration, it becomes easy to synchronizethe output of the image information 44 with the output of the integratedinformation 45.

Further, the image sensor 30 is also capable of displaying andoverwriting the integrated information 45 such as encrypted electronicsignature information or overwriting the integrated information 45 suchas electronic signature information as an electronic watermark in a partof the effective image frame of the image information 44 or the entireeffective image frame of the image information 44 and outputting theimage information 44. With this configuration, it becomes possible toreceive and send the integrated information 45 without the need forchanging the existing interface unit and it becomes easy to synchronizethe output of the image information 44 with the output of the integratedinformation 45.

Further, the image sensor 30 is also capable of displaying partial pixelinformation as partial pixel information in a part of the effectiveimage frame of the image information 44 or the entire effective imageframe of the image information 44, overwriting the integratedinformation 45 of electronic signature information that can bediscriminated and the like, and outputting the image information 44.With this configuration, it is possible to explicitly indicates that theimage information 44 is image information with the integratedinformation 45.

The image sensor 30 of this embodiment can also have a function whichenables the external unit to control a generation timing of theintegrated information 45 such as encrypted electronic signatureinformation. With this function, it is possible to reduce the generationload of the integrated information 45 and it becomes easy to synchronizethe output of the image information 44 with the output of the integratedinformation 45.

Further, the image sensor 30 can also have a function of controlling thegeneration timing of the integrated information 45 in accordance with adedicated control signal. With this function, by generating theintegrated information 45 only when a still image is taken, it ispossible to reduce the load and power consumption of the image sensor30.

In addition, the image sensor 30 can also have a function of setting ageneration cycle of the integrated information 45. With this function,it is possible to reduce the load and power consumption of the externalapparatus 43 that is on a developer side and the image sensor 30 whenthe integrated information 45 is regularly adding to a header for amoving image.

5. Second Image Information-Outputting Method

FIG. 5 is a schematic view for describing an imageinformation-outputting method of a second embodiment according to thepresent technology. This embodiment shows a mode to transmit imageinformation and integrated information from an image sensor to anexternal apparatus that is an example of the external unit via differenttransmission paths.

Image information 51 generated by an image sensor 50 of this embodimentis transmitted to an external apparatus 53 through an image transmissionpath 52 via an interface unit. Further, the image sensor 50 includes awrite register unit 54 and a read register unit 55. The write registerunit 54 receives a command signal of an instruction, control, and thelike of a timing and the like for generating the integrated information56 such as electronic signature information from the external apparatus53. The instruction includes, for example, an encryption instruction andthe like. The read register unit 55 controls output of the integratedinformation 56 and the like to the external apparatus 53 and the like.

The external apparatus 53 of this embodiment includes theintegrated-information analyzing unit 46 and an integrated-informationcontrol unit 57. The integrated-information analyzing unit 46 receivesand analyzes the image information 51 and the integrated information 56.The integrated-information control unit 57 outputs a command signal ofinstruction, control, and the like of a timing and the like forgenerating the integrated information 56 to the image sensor 50.

The image sensor 50 forms the integrated information 56 in accordancewith the command signal sent from the integrated-information controlunit 57 of the external apparatus 53 to the write register unit 54 via atransmission path 58. The image sensor 50 transmits the formedintegrated information 56 from the read register unit 55 to theintegrated-information analyzing unit 46 of the external apparatus 53via a transmission path 59. The external apparatus 53 which has receivedthe image information 51 and the integrated information 56 analyzes theintegrated information 56 at the integrated-information analyzing unit46 and identifies the image sensor 50.

The image sensor 50 of this embodiment is capable of outputting theintegrated information 56 such as encrypted electronic signatureinformation via the read register unit 55 of the image sensor 50. Withthis configuration, it becomes possible to receive and send theintegrated information 56 without changing an image input/outputinterface unit.

Further, the image sensor 50 can also have a function of outputting theintegrated information 56 associated with a frame ID of the imageinformation 51. With this function, it becomes easy to synchronize theoutput of the image information 51 of the image sensor 50 with theoutput of the integrated information 56.

6. Image Sensor-Identifying Method

FIG. 6 is a conceptual diagram for describing an imagesensor-identifying method of the embodiment according to the presenttechnology. FIG. 6 shows a flow of information to output the imageinformation 44 and the integrated information 45, for example, from theimage sensor 30 of FIG. 4 to the external apparatus 43 by using theimage sensor-identifying method of this embodiment.

Specifically, in Processing 601, the image sensor 30 acquires the imagesensor identification information of the image sensor 30. In Processing602, the image sensor 30 forms integrated information 45 in which theimage information 44 and the image sensor identification information areassociated with each other. Then, the image sensor 30 outputs the imageinformation 44 and the integrated information 45 to the externalapparatus 43.

In Processing 603, the external apparatus 43 acquires the imageinformation 44 and the integrated information 45 from the image sensor30. Then, in Processing 604, the external apparatus 43 analyzes theintegrated information 45 and identifies the image sensor 30 which hasgenerated the image information 44.

Here, the following three methods, for example, are conceivable as amethod of associating the image information with the image sensoridentification information. A first method includes direct association.Specifically, for example, information specific to the image sensor iscombined with information extracted from the image information inaccordance with a predetermined rule, and bit rows are simply connectedor rearrangement is performed in accordance with a certain rule. In thismethod, the image information is easily forged. However, the informationspecific to the image sensor is also included in the integratedinformation in which the image information and the image sensoridentification information are associated with each other, and thus alarge amount of information can be included in the integratedinformation.

A second method includes indirect association. Specifically, informationextracted from the image information is encrypted by using an encryptionkey specific to the image sensor. In this case, the information specificto each image sensor is only information corresponding to eachencryption key. In this method, it is difficult to forge the imageinformation. However, the information specific to sensor is not includedin the integrated information.

A third method includes a combination of the first and second methods.In this method, the forgery is difficult and a large amount ofinformation can be included in the integrated information.

In this embodiment, the external apparatus 43 is capable of analyzingthe image sensor identification information in the integratedinformation 45 acquired from the image sensor 30 and identifying theimage sensor 30 which has generated the image information 44. With thisconfiguration, the image sensor 30 of this embodiment is capable ofprocessing the image information 44 by using the image sensoridentification information.

FIG. 7 is a flowchart for describing an image sensor-identifying methodof the embodiment according to the present technology. Respectiveprocesses of the image sensor-identifying method of this embodiment willbe described with reference to FIG. 7.

In this embodiment, for example, a series of processing is started insuch a manner that the image information 44 obtained by the A/Dconversion unit 25 of the image information processing unit 4 providedin the signal processing substrate 23 of the image sensor 30 in FIG. 3is output to the integrated-information forming unit 26 of the imageinformation processing unit 4.

First of all, in Step S701, the integrated-information forming unit 26acquires the image sensor identification information of the image sensor30, which is generated by an identification information generating unitin the image information processing unit 4. Further, the imageinformation processing unit 4 can include an identification informationstorage unit that stores the image sensor identification information. Inthis case, during the manufacture of the image sensor 30, the imagesensor identification information can be stored in the identificationinformation storage unit. After the integrated-information forming unit26 acquires the image sensor identification information from theidentification information generating unit or the identificationinformation storage unit, the processing proceeds to Step S702.

In Step S702, the integrated-information forming unit 26 formsintegrated information 45 in which the acquired image sensoridentification information and the image information 44 obtained by theA/D conversion unit 25 are associated with each other. After the imageinformation 44 and the integrated information 45 are output from theimage information output unit 24 to the external apparatus 43 that is anexample of the external unit, the processing proceeds to Step S703.

Next, in Step S703, the integrated-information analyzing unit 46 of theexternal apparatus 43 acquires from the image information output unit 24to the image information 44 and the integrated information 45. After theimage information 44 and the integrated information 45 are acquired bythe integrated-information analyzing unit 46, the processing proceeds toStep S704.

In Step S704, the integrated-information analyzing unit 46 identifiesthe image sensor 30 which has generated the image information 44 on thebasis of the image sensor identification information in the integratedinformation 45, and then terminates the image sensor identificationprocessing.

In accordance with the above-mentioned image sensor-identifying method,in this embodiment, the acquired image information 44 and the imagesensor identification information of the image sensor 30 which hasgenerated the image information 44 are output to the external apparatus43 to be used by a user or the like in association with each other.Thus, it is possible to identify the image sensor 30 which has generatedthe image information 44.

Further, connected-apparatus information of the external apparatus 43that is a connection apparatus connected to the image sensor 30 can alsobe included in the integrated information 45 of this embodiment. Withthis configuration, it becomes possible to identify not only the imagesensor 30 but also the external apparatus 43 on which the image sensor30 is mounted. Thus, it becomes also possible to find an externalapparatus that should not use the image sensor 30. In addition, sincethe external apparatus 43 also includes apparatuses which affect theimage pickup condition such as a lens and an illumination apparatus, itis also possible to select processing suitable for these apparatuses andimprove the processing performance thereafter.

7. First Image Forgery-Preventing Method

FIG. 8 is a conceptual diagram for describing an imageforgery-preventing method of the first embodiment according to thepresent technology. FIG. 8 shows a flow of information to output theintegrated information in which the image information and the imagesensor identification information are encrypted and associated with eachother in accordance with the above-mentioned third method to theexternal apparatus and the like.

The image sensor according to the present technology is an image sensorthat performs encryption inside the image sensor by using a public-keymethod that is a well-known technique as an example of the encryptiontechnique and outputs the encrypted electronic signature information tothe external unit. It should be noted that the encryption according tothe present technology is not limited to the public-key method.

Here, the “public-key method” refers to cryptography in whichinformation is encrypted and decrypted by using two keys that are paired(public key and secret key). Note that a public key that can be used byan unspecified user and a secret key kept secret can be both used forencryption and decryption.

Specifically, in Processing 801, a manufacturer 80 for the image sensor30 of FIG. 4 generates a sensor key pair of a sensor public key and asensor secret key for performing encryption at the image sensor 30.After the sensor key pair is generated, the manufacturer 80 makes thesensor public key available publicly and writes the sensor secret key inthe image sensor 30.

In Processing 804, the image sensor 30 generates image information 44.In Processing 805, the image sensor 30 calculates a sensor hash value SHby using a hash function on the basis of the generated image information44. In Processing 806, the image sensor 30 encrypts the sensor hashvalue SH and the image sensor identification information of the imagesensor 30 by using the sensor secret key, to thereby form signatureinformation for the sensor that is an example of the integratedinformation 45. Then, the image sensor 30 outputs the image information44 and the signature information for the sensor to the externalapparatus 43 to be used by a user or the like at the same time.

Here, the “hash function” refers to a function for obtaining a numericalvalue that represents certain information. Further, the numerical valueobtained on the basis of the hash function refers to a hash value. In acase where the same hash function is used, the same hash value isobtained if base information is the same. On the other hand, in a casewhere the information is different, a different hash value is obtained.Note that the base information cannot be restored on the basis of thehash value. If the image information is encrypted as it is, thecomputation cost increases and the amount of electronic signatureinformation itself becomes huge. However, in a case where the hash valueis used, compression to fixed bits is performed while thealternation-detecting accuracy does not substantially change. Thus, itcan contribute to a reduction in computation cost and a reduction inamount of electronic signature information.

The external apparatus 43 that is on the image developer side acquiresthe output image information 44 with the signature information for thesensor and the sensor public key made available publicly. In Processing809, the external apparatus 43 decrypts the sensor hash value SHencrypted in the acquired signature information for the sensor by usingthe acquired sensor public key. Then, in Processing 810, the externalapparatus 43 calculates a hash function by using an image hash value RHon the basis of the acquired image information 44.

In Processing 811, the external apparatus 43 determines whether or notthe sensor hash value SH and the image hash value RH match each other.If the sensor hash value SH and the image hash value RH match eachother, the external apparatus 43 outputs an image, which is not forged,by using the acquired image information 44. If the sensor hash value SHand the image hash value RH do not match each other, the externalapparatus 43 does not output the image.

The image sensor 30 of this embodiment outputs the signature informationfor the sensor in which the generated image information 44 and the imagesensor identification information of the image sensor 30 which hasgenerated the image information 44 are associated with each other andare encrypted to the external apparatus 43. Thus, it is possible toidentify the image sensor 30 which has generated the image information44 and it is possible to prevent forgery and alternation of the imageinformation 44.

Note that as the method of making the key available publicly accordingto the present technology, there is also a method in which theinformation of the sensor public key is written in the read registerunit 55 of the image sensor 50 of FIG. 5, for example. With this method,even if the sensor public key is a sensor public key specific to allimage sensors, it becomes possible to easily make it available publicly.Further, as the method of making the key available publicly according tothe present technology, there is also a method in which the image sensor50 makes the information of the sensor public key available publicly ona public document or on the web. With this method, a third party caneasily check the integrated information 56 such as encrypted electronicsignature information.

FIG. 9 is a flowchart for describing an image forgery-preventing methodof the first embodiment according to the present technology. Respectiveprocesses of the image forgery-preventing method of this embodiment willbe described with reference to FIG. 9.

First of all, in Step S901, the manufacturer 80 for the image sensor 30generates a sensor key pair of a sensor public key and a sensor secretkey for performing encryption at the image sensor 30. After the sensorkey pair is generated, the processing proceeds to Step S902.

In Step S902, the manufacturer 80 makes the sensor public key availablepublicly. After the sensor public key is made available publicly, theprocessing proceeds to Step S903.

In Step S903, the manufacturer 80 writes the sensor secret key in theimage sensor 30. After the sensor secret key is written in the imagesensor 30, the processing proceeds to Step S904.

Next, in Step S904, the A/D conversion unit 25 of the image sensor 30receives electrical signals from the sensor unit 21 and generates imageinformation 44. After the image information 44 is generated by the A/Dconversion unit 25, the processing proceeds to Step S905.

In Step S905, the integrated-information forming unit 26 of the imagesensor 30 calculates a sensor hash value SH by using the hash functionon the basis of the generated image information 44. After the sensorhash value SH is calculated by the integrated-information forming unit26, the processing proceeds to Step S906.

In Step S906, the integrated-information forming unit 26 encrypts thesensor hash value SH and the image sensor identification information ofthe image sensor 30 by using the sensor secret key, to thereby formsignature information for the sensor that is an example of theintegrated information 45. After the signature information for thesensor is formed by the integrated-information forming unit 26, theprocessing proceeds to Step S907.

In Step S907, the image information output unit 24 of the image sensor30 outputs the generated image information 44 and the signatureinformation for the sensor to the external apparatus 43 to be used by auser or the like at the same time. After the image information 44 withthe signature information for the sensor is output to the externalapparatus 43, the processing proceeds to Step S908.

Next, in Step S908, the integrated-information analyzing unit 46 of theexternal apparatus 43 acquires the image information 44 with thesignature information for the sensor, which has been output by the imageinformation output unit 24, and the sensor public key made availablepublicly by the manufacturer 80. After the image information 44 with thesignature information for the sensor and the sensor public key areacquired by the integrated-information analyzing unit 46, the processingproceeds to Step S909.

In Step S909, the integrated-information analyzing unit 46 decrypts thesensor hash value SH encrypted in the acquired signature information forthe sensor by using the acquired sensor public key. After the sensorhash value SH is decrypted by the integrated-information analyzing unit46, the processing proceeds to Step S910.

In Step S910, as in the integrated-information forming unit 26, theintegrated-information analyzing unit 46 calculates an image hash valueRH by using the hash function on the basis of the acquired imageinformation 44. After the image hash value RH is calculated by theintegrated-information analyzing unit 46, the processing proceeds toStep S911.

In Step S911, the integrated-information analyzing unit 46 determineswhether or not the sensor hash value SH and the image hash value RHmatch each other.

In Step S911, if YES, i.e., the sensor hash value SH and the image hashvalue RH match each other, the processing proceeds to Step S912, and theexternal apparatus 43 outputs an image, which is not forged, by usingthe acquired image information 44, and then terminates the imageforgery-preventing processing. In Step S911, if NO, i.e., if the sensorhash value SH and the image hash value RH do not match each other andthe acquired image information 44 is forged or altered, and thus theexternal apparatus 43 terminates the image forgery-preventing processingwithout outputting the image.

In the above-mentioned image forgery-preventing method, the image sensor30 of this embodiment outputs the signature information for the sensorin which the generated image information 44 and the image sensoridentification information of the image sensor 30 which has generatedthe image information 44 are associated with each other and areencrypted to the external apparatus 43. Thus, it is possible to identifythe image sensor 30 which has generated the image information 44 and itis possible to prevent forgery and alternation of the image information44.

In this embodiment, the sensor hash value SH and the image sensoridentification information are encrypted and the signature informationfor the sensor is formed by using the secret key. With thisconfiguration, anyone of a third party can authenticate the imageinformation 44 utilizing this signature information for the sensor.

Further, the image sensor 30 of this embodiment includes a mechanismthat outputs the signature information for the sensor and the imageinformation 44 at the same time. With this configuration, it becomespossible to form, immediately after the conversion by the A/D conversionunit 25, the signature information for the sensor under ahighest-reliability condition, that is, before the output by theexternal apparatus 43 which is an external unit with respect to theimage sensor 30

Further, as shown in FIG. 3, in such a manner that the signal processingsubstrate 23 is covered with the three-layer stacked image sensor 30,the image sensor 30 of this embodiment includes a mechanism thatconceals the information of the sensor secret key and prevents it frombeing read from the external unit. With this configuration, the secretkey written in the image sensor 30 can be protected from a maliciousthird party. In addition, by preventing the external unit from easilyanalyzing the information of the sensor secret key, it is also possibleto prevent reading.

In accordance with the image forgery-preventing method of thisembodiment, it becomes possible for a user to identify the type of theimage sensor by checking matching of the hash values, and the imageinformation can be prevented from being forged. Thus, it is possible toperform development processing specialized for the image sensor.Further, it is also possible to selectively implement high-image qualitydevelopment processing optimal to image pickup characteristics of theimage sensor. Further, it is also possible to feed back optimal settingswhen image pickup is performed to the image sensor. With theseconfigurations, it becomes possible to freely provide signal processingsoftware for the purpose of promoting sales of image sensors.

In addition, in accordance with the image forgery-preventing method ofthis embodiment, the image information can be prevented from beingcopied and altered due to individual discrimination of the image sensorand an image sensor which has picked up an image can be identified.Thus, it is possible to protect the copyright of a digital image takenby a user who uses the image sensor. Further, it is possible toguarantee that the image information is not altered in thehighest-reliability phase, that is, after A/D conversion. Thus, a highcapability for a crime evidence can be provided.

8. Second Image Forgery-Preventing Method

FIG. 10 is a conceptual diagram for describing an imageforgery-preventing method of the second embodiment according to thepresent technology.

As shown in FIG. 10, in this embodiment, a flow of information to outputthe integrated information in which the image information and the imagesensor identification information are encrypted and associated with eachother in accordance with the above-mentioned third method to theexternal apparatus and the like and to issue a certificate forauthentication is shown.

Here, the “certificate” refers to electromagnetic information to be usedfor checking that a user has made an electronic signature. Further, the“electronic signature” refers to a signature to be made on an electronicdocument, which is for checking consistency between electronic documentsand also checking an author thereof. Note that the certificate can beissued by a manufacturer for the image sensor or a certificate authority(CA) that is a third-party organization that guarantees the validity ofthe electronic signature.

Specifically, in Processing 1001, a manufacturer 100 for the imagesensor 30 of FIG. 4 generates a sensor key pair of a sensor public keySK and a sensor secret key for performing encryption at the image sensor30. After the sensor key pair is generated, the manufacturer 100 writesthe sensor secret key in the image sensor 30.

Further, in Processing 1002, the manufacturer 100 generates a key pairfor authentication of a public key for authentication and a secret keyfor authentication for certificate generation. After the key pair forauthentication is generated, the manufacturer 100 makes the public keyfor authentication available publicly. In Processing 1004, themanufacturer 100 encrypts the sensor public key SK and its ownerinformation by using the secret key for authentication, to thereby formsignature information for authentication. In Processing 1005, themanufacturer 100 generates a certificate in which the sensor public keySK and the signature information for authentication are written andissues it to the external apparatus 43 via the image sensor 30.

In Processing 1007, the image sensor 30 generates image information 44.In Processing 1008, the image sensor 30 calculates a sensor hash valueSH by using the hash function on the basis of the generated imageinformation 44. In Processing 1009, the image sensor 30 encrypts thesensor hash value SH and the image sensor identification information ofthe image sensor 30 by using the sensor secret key, to thereby formsignature information for the sensor that is an example of theintegrated information 45. Then, the image sensor 30 outputs the imageinformation 44 and the signature information for the sensor to theexternal apparatus 43 to be used by a user or the like at the same time.

The external apparatus 43 that is on the image developer side acquiresthe output image information 44 with the signature information for thesensor, the certificate issued by the manufacturer 100, and the publickey for authentication made available publicly by the manufacturer 100.In Processing 1012, the external apparatus 43 decrypts the encryptedsensor public key CK in the signature information for authentication ofthe acquired certificate by using the acquired public key forauthentication. In Processing 1013, the external apparatus 43 determineswhether or not the decrypted sensor public key CK and the sensor publickey SK in the certificate match each other.

If both the sensor public keys match each other, in Processing 1014, theexternal apparatus 43 decrypts the sensor hash value SH encrypted in theacquired signature information for the sensor by using the sensor publickey SK in the certificate. In Processing 1015, the external apparatus 43calculates an image hash value RH by using the hash function on thebasis of the acquired image information 44.

In Processing 1016, the external apparatus 43 determines whether or notthe sensor hash value SH and the image hash value RH match each other.If the sensor hash value SH and the image hash value RH match eachother, the external apparatus 43 outputs an image, which is not forged,by using the acquired image information 44. If the sensor hash value SHand the image hash value RH do not match each other, the externalapparatus 43 does not output the image.

In this embodiment, in addition to the effect of the firstforgery-preventing method, the electronic signature information usingthe certificate issued from the manufacturer 100 or the certificateauthority (CA) makes it possible to not only detect falsification of theimage information but also check that the sensor public key is correct.Thus, the image sensor 30 can be more reliably identified.

FIGS. 11A and 11B are flowcharts for describing the imageforgery-preventing method of the second embodiment according to thepresent technology. Respective processes of the image forgery-preventingmethod of this embodiment will be described with reference to FIGS. 11Aand 11B.

In Step S1101 of FIG. 11A, the manufacturer 100 for the image sensor 30generates a sensor key pair of a sensor public key SK and a sensorsecret key for performing encryption at the image sensor 30. After thesensor key pair is generated, the processing proceeds to Step S1102.

In Step S1102, the manufacturer 100 generates a key pair forauthentication of a public key for authentication and a secret key forauthentication for certificate generation. After the key pair forauthentication is generated, the processing proceeds to Step S1103

In Step S1103, the manufacturer 100 makes the public key forauthentication available publicly and sends it to the external apparatus43 that is on the developer side. After the public key forauthentication is made available publicly, the processing proceeds toStep S1104.

In Step S1104, the manufacturer 100 encrypts the sensor public key SKand its owner information by using the secret key for authentication, tothereby form signature information for authentication. After thesignature information for authentication is formed, the processingproceeds to Step S1105.

In Step S1105, the manufacturer 100 generates a certificate in which thesensor public key SK and the signature information for authenticationare written and issues it to the external apparatus 43 via the imagesensor 30. After the certificate is issued, the processing proceeds toStep S1106.

In Step S1106, the manufacturer 100 writes the sensor secret key in theimage sensor 30. After the sensor secret key is written in the imagesensor 30, the processing proceeds to Step S1107.

Next, in Step S1107, the A/D conversion unit 25 of the image sensor 30receives electrical signals from the sensor unit 21 and generates imageinformation 44. After the image information 44 is generated by the A/Dconversion unit 25, the processing proceeds to Step S1108.

In Step S1108, the integrated-information forming unit 26 of the imagesensor 30 calculates a sensor hash value SH by using the hash functionon the basis of the generated image information 44. After the sensorhash value SH is calculated by the integrated-information forming unit26, the processing proceeds to Step S1109.

In Step S1109, the integrated-information forming unit 26 encrypts thesensor hash value SH and the image sensor identification information ofthe image sensor 30 by using the sensor secret key, to thereby formsignature information for the sensor that is an example of theintegrated information 45. After the signature information for thesensor is formed by the integrated-information forming unit 26, theprocessing proceeds to Step S1110.

In Step S1110, the image information output unit 24 outputs thegenerated image information 44 and the signature information for thesensor that is an example of the integrated information 45 to theexternal apparatus 43 to be used by a user or the like at the same time.After the image information 44 with the signature information for thesensor is output to the external apparatus 43, the processing proceedsto Step S1111 of FIG. 11B.

In Step S1111 of FIG. 11B, the integrated-information analyzing unit 46of the external apparatus 43 that is on the image developer sideacquires the image information 44 with the signature information for thesensor, which has been output by the image information output unit 24,the certificate issued by the manufacturer 100, and the public key forauthentication made available publicly by the manufacturer 100. Afterthese pieces of information are acquired by the integrated-informationanalyzing unit 46, the processing proceeds to Step S1112.

In Step S1112, the integrated-information analyzing unit 46 decrypts theencrypted sensor public key CK in the signature information forauthentication of the acquired certificate by using the acquired publickey for authentication. After the sensor public key CK is decrypted bythe integrated-information analyzing unit 46, the processing proceeds toStep S1113.

In Step S1113, the integrated-information analyzing unit 46 determineswhether or not the decrypted sensor public key CK and the sensor publickey SK in the certificate match each other.

In Step S1113, if YES, i.e., if the decrypted sensor public key CK andthe sensor public key SK in the certificate match each other, theprocessing proceeds to Step S1114. In Step S1113, if NO, i.e., if thedecrypted sensor public key CK and the sensor public key SK in thecertificate do not match each other, the acquired sensor public key isnot valid, and thus the external apparatus 43 terminates the imageforgery-preventing processing without outputting the image.

In Step S1114, the integrated-information analyzing unit 46 decrypts theencrypted sensor hash value SH by using the sensor public key SK in thecertificate. After the sensor hash value SH is decrypted by theintegrated-information analyzing unit 46, the processing proceeds toStep S1115.

In Step S1115, as in the integrated-information forming unit 26, theintegrated-information analyzing unit 46 calculates an image hash valueRH by using the hash function on the basis of the acquired imageinformation 44. After the image hash value RH is calculated by theintegrated-information analyzing unit 46, the processing proceeds toStep S1116.

In Step S1116, the integrated-information analyzing unit 46 determineswhether or not the sensor hash value SH and the image hash value RHmatch each other.

In Step S1116, if YES, i.e., if the sensor hash value SH and the imagehash value RH match each other, the processing proceeds to Step S1117,and the external apparatus 43 outputs an image, which is not forged, byusing the acquired image information 44, and then terminates the imageforgery-preventing processing. In Step S1116, if NO, i.e., if the sensorhash value SH and the image hash value RH do not match each other, theacquired image information 44 is forged or altered, and thus theexternal apparatus 43 terminates the image forgery-preventing processingwithout outputting the image.

In accordance with the image forgery-preventing method of thisembodiment, in addition to the effect of the first forgery-preventingmethod, the signature information for authentication using thecertificate issued from the manufacturer 100 makes it possible to notonly detect falsification of the image information 44 but also checkthat the sensor public key SK is correct. Thus, the image sensor 30 canbe more reliably identified.

9. Image Alternation-Limiting Method

FIG. 12 is a flowchart for describing an image alternation-limitingmethod according to the embodiment of the present technology. Respectiveprocesses of the image alternation-limiting method of this embodimentwill be described with reference to FIG. 12. Here, the series ofprocessing is started, for example, after the image information 44 istransmitted from the image sensor 30 of FIG. 4 to the external apparatus43, which is a connection apparatus connected to the image sensor 30 andthe image is developed by the external apparatus 43.

First of all, in Step S1201, the integrated-information analyzing unit46 of the external apparatus 43 calculates an image hash value DH afterdevelopment on the basis of image information after development. Afterthe image hash value DH after development is calculated by theintegrated-information analyzing unit 46, the processing proceeds toStep S1202.

In Step S1202, the integrated-information analyzing unit 46 transmitsthe image hash value DH after development, which is calculated in StepS1201, and a part of the image after development to the image sensor 30.After the image hash value DH after development and the part of theimage after development are transmitted to the image sensor 30, theprocessing proceeds to Step S1203.

Next, in Step S1203, the integrated-information forming unit 26 of theimage sensor 30 acquires the image hash value DH after development andthe part of the image after development, which have been transmittedfrom the external apparatus 43. After the image hash value DH afterdevelopment and the part of the image after development are acquired bythe integrated-information forming unit 26, the processing proceeds toStep S1204.

In Step S1204, the integrated-information forming unit 26 determines adegree of similarity by comparing image information before developmentwith the acquired image information after development.

The determination of the degree of similarity is performed in such amanner that a degree-of-similarity indicative value S of the imageinformation before development and the acquired image information afterdevelopment is compared with a threshold T and the electronic signatureinformation is formed only in a case where it satisfies at least apredetermined condition. Note that although there are various methodssuch as SSD, SAD, NCC, and ZNCC for the degree-of-similarity indicativevalue S, zero-mean normalized cross-correlation (ZNCC) with lessinfluence of brightness change after development will be described as anexample in the present technology. If the degree-of-similarityindicative value S is smaller than the threshold T (S<T), theintegrated-information forming unit 26 determines that the degree ofsimilarity is high, and generates electronic signature information. Thedegree-of-similarity indicative value S indicates a lower degree ofsimilarity as that value becomes larger. In a case where thedegree-of-similarity indicative value S is equal to or larger than thethreshold T (S≥T), the integrated-information forming unit 26 determinesthat the degree of similarity is low and does not generate theelectronic signature information.

In Step S1204, if it is determined that the degree of similarity is low,the processing proceeds to Step S1205. Since it is determined that theacquired image information is forged or altered, theintegrated-information forming unit 26 terminates the image alternationlimiting processing without generating the signature. In Step S1204, ifit is determined that the degree of similarity is high, the processingproceeds to Step S1206.

In Step S1206, the integrated-information forming unit 26 encrypts theacquired image hash value DH after development by using the sensorsecret key, to thereby form signature information after development.After the signature information after development is formed by theintegrated-information forming unit 26, the processing proceeds to StepS1207.

In Step S1207, the image information output unit 24 outputs thesignature information after development formed in Step S1206 to theexternal apparatus 43. After the signature information after developmentis output to the external apparatus 43, the processing proceeds to StepS1208.

Next, in Step S1208, the integrated-information analyzing unit 46 of theexternal apparatus 43 acquires the signature information afterdevelopment output by the image information output unit 24. After thesignature information after development is acquired by theintegrated-information analyzing unit 46, the processing proceeds toStep S1209.

In Step S1209, the integrated-information analyzing unit 46 outputs theimage after development and the acquired signature information afterdevelopment in association with each other to another external unitconnected to the external apparatus 43, and then terminates the imagealternation limiting processing. Note that the image after developmentwith the signature information after development, which has been outputto the other external unit, can be output from the other external unitin steps similar to Steps S908 to S912 of FIG. 9.

In accordance with the image alternation limiting processing method ofthis embodiment, the signature information after development is added tothe image after development and is output to the external unit. Thus,the image alternation privilege can be added only to the imageinformation after development, which is obtained by performingdecryption processing on the image information 44 generated by the imagesensor 30. With this configuration, it is possible to limit alternationwith respect to an image obtained on the basis of image informationgenerated by a unit other than the image sensor 30. As an example, onlya user having a privilege to decrypt is enabled to use a developmentapplication service such as particular image correction processing.

10. Various Generation Methods for Electronic Signature Information

The generation method for the electronic signature information accordingto the present technology can take the following modes in addition tothe above-mentioned embodiments.

The image sensor according to the present technology is capable ofincluding information based on a picked-up image in the electronicsignature information and encrypting and outputting it. With thisconfiguration, the image information and the electronic signatureinformation can be associated with each other

As an example, hash value information generated on the basis of theimage information or part of the image information can be included inthe electronic signature information. With this configuration,large-amount image information can be associated with the electronicsignature information with low computation load.

As another example, reduced-image information can also be included inthe electronic signature information. With this configuration, featuresof the image information can be determined by using only the electronicsignature information.

As another example, by performing development inside the image sensorand then outputting the image after development, information based onthe image after development can also be included in in the electronicsignature information. With this configuration, the electronic signatureinformation associated with the image after development can be generatedinside the image sensor.

As another example, by performing development or compression inside theimage sensor and then outputting the compressed image, information basedon the compressed image can also be included in the electronic signatureinformation. With this configuration, the electronic signatureinformation associated with the compressed image can be generated insidethe image sensor.

Further, the image sensor according to the present technology is capableof including information specific to the image sensor in the electronicsignature information and encrypting and outputting it. With thisconfiguration, it becomes possible to identify the image sensor whichhas generated the electronic signature information.

As an example, identifiers specific to all image sensors can be includedin the electronic signature information. With this configuration, itbecomes possible to identify all the image sensors which have generatedthe electronic signature information.

As another example, a frame counter value that cannot be reset, which isretained also when the power supply is off, can also be included in theelectronic signature information. With this configuration, a time(order) when the electronic signature information was generated can beroughly estimated.

Further, the image sensor according to the present technology is capableof including information regarding the image pickup condition of theimage in the electronic signature information and encrypting andoutputting it. With this configuration, a condition when the image ispicked up can be determined on the basis of the electronic signatureinformation.

As an example, GPS information can be included in the electronicsignature information. With this configuration, a place where theelectronic signature information was generated can be determined. Asanother example, time information can also be included in the electronicsignature information. With this configuration, a time at which theelectronic signature information was generated can be determined.

Further, the image sensor according to the present technology is capableof including information received from the external unit in theelectronic signature information and encrypting and outputting it. Withthis configuration, the electronic signature information that certifiesthat it is a system connected to the image sensor can be generated.

Further, the image sensor according to the present technology is capableof including additionally encrypted information in the electronicsignature information and encrypting and outputting it. With thisconfiguration, only a person who can decipher the additionally encryptedinformation can get profit from that information.

11. Various Encryption Methods for Electronic Signature Information

The encryption method for the electronic signature information accordingto the present technology can take the following modes in addition tothe above-mentioned embodiments.

The image sensor according to the present technology is capable ofencrypting the electronic signature information by using a sensor key ofencryption which is written during the manufacture of the image sensor.With this configuration, a person who generates an encryption key can belimited to a manufacturer, and thus alternation and forgery of thesensor key can be prevented.

As an example, it is possible to generate sensor key pairs specific toall image sensors and write a sensor secret key in each image sensor orto generate a large number of sensor key pairs and randomly write sensorsecret keys in the image sensors. These configurations provide anadvantage in that even if a sensor secret key is deciphered, only oneimage will suffer from damage.

As another example, it is also possible to set an arbitrary sensor keyfrom the external unit and encrypt the electronic signature informationby using it. With this configuration, not only an image sensormanufacturer but anyone can freely set a sensor key.

As another example, it is also possible to generate a sensor key pairinside the image sensor and output encrypted electronic signatureinformation and a public key. With this configuration, if the sensor keyis deciphered, damage is limited to a signature using the sensor keygenerated at that time. Thus, extremely high safety can be secured.

12. Various Reissue Methods for Electronic Signature Information afterDevelopment

Moreover, the reissue method for electronic signature information afterdevelopment according to the present technology can take the followingmodes.

The image sensor according to the present technology is capable ofissuing the electronic signature information only in a case where theimage output from the image sensor is developed. With thisconfiguration, it is possible to generate electronic signatureinformation based on not a raw image but information of the imageinformation after development.

As an example, only in a case where the degree of similarity with theimage information before development is high when the image informationafter development is acquired, the electronic signature information canbe issued. With this configuration, the image sensor does not operate ifan image is not a picked-up image, and thus spoofing can be prevented.

As another example, the image sensor can include a mechanism forchecking direct connection to the external unit and the electronicsignature information can be issued only when the connection isverified. With this configuration, the electronic signature informationcan be issued only to a system whose connection to the image sensor hasbeen verified, and thus spoofing can be prevented.

As another example, the electronic signature information can be issuedonly under a condition authenticated in accordance with an externalauthentication program. With this configuration, the external programcan ensure the reliability of the issued electronic signatureinformation of the image after development.

13. Addition Method for Reliability Information

Next, a method of adding reliability information when the electronicsignature information of the image after development is generated willbe described. The reliability information is added by adding, to theelectronic signature information, the degree-of-similarity indicativevalue S of the images before and after development by using the ZNCCmethod, for example.

Specifically, there is a method of comparison using a single color (onlygreen components) or a method of comparison using luminance components(Y=R+G+B). With these methods, even a difference between raw imageinformation before development and image information after development(RGB data) can be correctly obtained. Further, there is a method ofdetermining a difference of a reduced image or a cropped image in orderto reduce the processing of comparison.

The image sensor according to the present technology is capable ofadding the reliability information when the electronic signatureinformation of the image after development is generated as describedabove. With this configuration, it is possible to provide a degree offreedom in verification of the electronic signature information.

As another example, it is possible to compare the image beforedevelopment with the image after development and include a quantitativenumerical value of the degree of similarity in the electronic signatureinformation and issue it. With this configuration, the system thereaftercan be notified of it as the reliability information of the electronicsignature information.

As another example, it is possible to issue electronic signatureinformation, to which information indicating that it is the electronicsignature information of the image after development is added, and writethe number of times of issue. With this configuration, the systemthereafter can be notified of it as the reliability information of theelectronic signature information.

14. Application Service

Next, a mode of an application service according to the presenttechnology will be described.

There is a copy and alternation-preventing service (e.g., SNS andcopy-preventing function) utilizing individual identification of theimage sensor. With this service, the image sensor can be identified, andthus spoofing becomes difficult.

Further, selective processing (e.g., optimal processing selection andsensor limitation processing) thereafter utilizing type identificationof the image sensor can be performed. With this configuration, itbecomes possible to promote sales of image sensors and optimize theimage equality according to the image sensor.

In addition, a reissue service of the electronic signature informationof the image after development can be provided by using the sensorsecret key managed by the manufacturer. With this configuration, it ispossible to check the electronic signature information and provide aservice that reissues the electronic signature information by using thesensor secret key of that image sensor.

With the above-mentioned configurations and methods, a camera (imagesensor) which has picked up an image can be identified in accordancewith the present technology. Further, it becomes possible to preventoutput raw image information from being easily forged (improperly used)by copying and altering it. In addition, the type of the image sensorcan be determined on the developer side and thus a development methodother than a general-purpose development method (also applicable toimage) can be realized.

Further, although electronic information (digital data) is easilycopied, optical (analog) information cannot be copied. Even if theelectronic signature information is added to the image information andguaranteed by the external unit with respect to the image sensor, thereis always a risk that original image information is a copy. However, bygenerating the electronic signature information inside the image sensor,it is possible to guarantee that the original image information is not acopy. Therefore, in this embodiment, the electronic signatureinformation is generated inside the image sensor, and thus it isextremely advantageous for guaranteeing consistency between digitalimage information and a real image.

15. Configuration Example of Personal Computer

FIG. 13 is a schematic view showing a configuration example of an imagepickup apparatus according to the present technology and a personalcomputer that performs data communication. FIG. 13 shows a configurationexample of an embodiment of a personal computer in which programs forexecuting the above-mentioned series of processing are installed.

The above-mentioned series of processing of the present technology maybe executed by dedicated hardware or may be executed by software. In acase where the series of processing is executed by software, programsconfiguring the software are installed in a general-purpose computer orthe like.

The computer of this embodiment includes a built-in central processingunit (CPU) 1301. A read only memory (ROM) 1303, a random access memory(RAM) 1304, a hard disk 1305, and an input/output interface unit 1306are connected to the CPU 1301 via a bus 1302.

When a command is input into the CPU 1301 by, for example, a useroperating an input unit 1307 including a keyboard, a mouse, amicrophone, and the like via the input/output interface unit 1306, theCPU 1301 executes programs stored in the ROM 1303 in accordance with it.Further, the CPU 1301 loads programs stored in the hard disk 1305,programs transferred from a satellite or a network, received by acommunication unit 1308, and installed in the hard disk 1305, orprograms read from a removable recording medium 1310 mounted on a drive1309 and installed in the hard disk 1305 into the RAM 1304 and executesthe loaded programs.

In the above-mentioned manner, the CPU 1301 performs the processingaccording to the above-mentioned flowcharts or processing performed bythe configuration of the above-mentioned block diagram. Then, the CPU1301 outputs a processing result thereof from an output unit 1311including a liquid crystal display (LCD), a speaker, and the like viathe input/output interface unit 1306, for example, in a manner thatdepends on needs, or transmits the processing result from thecommunication unit 1308 and further causes the hard disk 1305 to recordthe transmitted processing result, for example

The programs can be recorded in the hard disk 1305 and the ROM 1303which are built-in recording media of the computer.

Further, the programs can be temporarily or permanently stored(recorded) in the removable recording medium 1310 such as a flexibledisk, a compact disc read only memory (CD-ROM), a magneto-optical (MO)disk, a digital versatile disc (DVD), a magnetic disk, and asemiconductor memory. Such a removable recording medium 1310 can beprovided as so-called package software.

Note that rather than being installed in the computer from the removablerecording medium 1310 as described above, the programs can be wirelesslytransferred to the computer from a downloading site via an artificialsatellite for digital satellite broadcasting or can be wiredlytransferred to the computer via a network such as a local area network(LAN) and the Internet, and in the computer, the programs transferred inthis manner can be received by the communication unit 1308 and installedin the built-in hard disk 1305.

Here, herein, the processing steps that describe programs for causingthe computer to execute various types of processing do not necessarilyneed to be processed sequentially in the order described as eachflowchart, and also include processing executed concurrently orindividually (e.g., concurrent processing or processing by object).

Further, the programs may be processed by one computer or may bedistributed to and processed by a plurality of computers. In addition,the programs may be transferred to and executed by a remote computer.

Note that embodiments of the present technology are not limited to theabove-mentioned embodiments, and various modifications can be madewithout departing from the gist of the present technology. For example,a mode combining all or some of the above-mentioned plurality ofembodiments can be employed.

Further, the present technology can take the following configurations.

(1) An image sensor, at least including:

an image information processing unit that forms integrated informationin which image sensor identification information capable of identifyingthe image sensor and image information obtained by an analog/digitalconversion unit are associated with each other; and

an image information output unit that outputs the integrated informationto an external unit.

(2) The image sensor according to (1), in which

the integrated information is electronic signature information obtainedby encrypting the image sensor identification information and/or theimage information.

(3) The image sensor according to (2), in which

the electronic signature information is formed in accordance with anencryption instruction from the external unit.

(4) The image sensor according to (2), in which

the electronic signature information is output to the external unit viaa read register unit.

(5) The image sensor according to (2), in which

the electronic signature information is output to the external unit viaan interface unit.

(6) The image sensor according to (2), in which

the electronic signature information includes an image pickup condition.

(7) The image sensor according to (2), in which

the electronic signature information is information obtained byencrypting a hash value calculated on a basis of the image information.

(8) The image sensor according to (2), in which

the electronic signature information is output such that the electronicsignature information is displayed in part of the image information.

(9) The image sensor according to (2), in which

the electronic signature information includes connected-apparatusinformation regarding an apparatus connected to the image sensor.

(10) The image sensor according to (2), in which

the electronic signature information is information encrypted inaccordance with a public-key method.

(11) The image sensor according to (10), in which

the electronic signature information is information encrypted by using asecret key.

(12) The image sensor according to (10), in which

the electronic signature information is information including acertificate that authenticates a public key.

(13) The image sensor according to (2), in which

the electronic signature information further includes information formedby using image information after development of the image informationoutput to the external unit.

(14) The image sensor according to (13), in which

the electronic signature information is formed only in a case where adegree of similarity between the image information and the imageinformation after development satisfies at least a predeterminedcondition.

(15) The image sensor according to (2), including

a three-layer stacking structure having a configuration in which asignal processing substrate including the image information processingunit is provided between a pixel substrate and a memory substrate.

(16) An image pickup apparatus, at least including

an image sensor including

-   -   an image information processing unit that forms integrated        information in which image sensor identification information        capable of identifying the image sensor and image information        obtained by an analog/digital conversion unit are associated        with each other, and    -   an image information output unit that outputs the integrated        information to an external unit.

(17) An image sensor-identifying method, including

identifying an image sensor by analyzing integrated information in whichimage sensor identification information capable of identifying the imagesensor and image information obtained by an analog/digital conversionunit are associated with each other, the integrated information beingoutput from the image sensor to an external unit.

(18) An image forgery-preventing method, including

preventing forgery of image information by using electronic signatureinformation in which image sensor identification information capable ofidentifying an image sensor and image information obtained by ananalog/digital conversion unit are associated with each other and areencrypted, the electronic signature information being output from theimage sensor to an external unit.

(19) An image alternation-limiting method, including

giving an image alternation privilege only to decrypted imageinformation obtained by performing decryption processing on imageinformation including electronic signature information in which imagesensor identification information capable of identifying an image sensorand the image information obtained by an analog/digital conversion unitare associated with each other and are encrypted, the image informationbeing output from the image sensor to an external unit.

REFERENCE SIGNS LIST

-   1 image pickup apparatus-   2 power supply circuit-   3 image pickup lens-   4 image information processing unit-   5 display processing unit-   6 display unit-   7 camera control unit-   8 image recording control unit-   9 image recording unit-   10, 20, 30, 50 image pickup element (image sensor)-   11 power supply line-   12 to 17 signal line-   21 sensor unit-   22 pixel substrate-   23 signal processing substrate-   24 image information output unit-   25 analog/digital conversion unit (A/D conversion unit)-   26 integrated-information forming unit-   31 memory substrate-   42, 52, 58, 59 transmission path-   43, 53 external apparatus-   44, 51 image information-   45, 56 integrated information-   46 integrated-information analyzing unit-   54 write register unit-   55 read register unit-   57 integrated-information control unit-   80, 100 manufacturer-   1301 CPU-   1302 bus-   1303 ROM-   1304 RAM-   1305 hard disk-   1306 input/output interface unit-   1307 input unit-   1308 communication unit-   1309 drive-   1310 removable recording medium-   1311 output unit

1. An apparatus, comprising: an integrated-information analyzing deviceconfigured to: receive data of an image sensor, wherein the dataincludes image information and integrated information; and identify theimage sensor based on analysis of the data, wherein the imageinformation is obtained by an analog/digital conversion device of theimage sensor.
 2. The apparatus according to claim 1, wherein theintegrated information is based on identification information of theimage sensor.
 3. The apparatus according to claim 2, wherein theintegrated information is generated using a hash function.
 4. Theapparatus according to claim 1, wherein the integrated informationincludes electronic signature information obtained by encryption ofidentification information of the image sensor.
 5. The apparatusaccording to claim 4, wherein the electronic signature information isencrypted by a public-key method.
 6. The apparatus according to claim 4,wherein the electronic signature information is encrypted by a secretkey.
 7. The apparatus according to claim 4, wherein the electronicsignature information is displayed in a part of the image information.8. The apparatus according to claim 4, wherein the electronic signatureinformation includes an image pickup condition.
 9. The apparatusaccording to claim 1, wherein the integrated information includeselectronic signature information obtained by encryption of a hash valuegenerated by the image sensor.
 10. A method, comprising: receiving dataof an image sensor, wherein the data includes image information andintegrated information; and identifying the image sensor based onanalysis of the data, wherein the image information is obtained by ananalog/digital conversion device of the image sensor.
 11. The methodaccording to claim 10, wherein the integrated information is based onidentification information of the image sensor.
 12. The method accordingto claim 11, wherein the integrated information is generated using ahash function.
 13. The method according to claim 10, wherein theintegrated information includes electronic signature informationobtained by encryption of identification information of the imagesensor.
 14. The method according to claim 13, wherein the integratedinformation includes the electronic signature information.
 15. Themethod according to claim 14, wherein the electronic signatureinformation is encrypted by a public-key method.
 16. The methodaccording to claim 14, wherein the electronic signature information isencrypted by a secret key.
 17. The method according to claim 14, whereinthe electronic signature information is displayed in a part of the imageinformation.
 18. The method according to claim 14, wherein theelectronic signature information includes an image pickup condition. 19.The method according to claim 10, wherein the integrated informationincludes electronic signature information obtained by encryption of ahash value generated by the image sensor.
 20. A non-transitorycomputer-readable medium having stored thereon computer-executableinstructions that, when executed by a processor, cause the processor toexecute operations, the operations comprising: receiving data of animage sensor, wherein the data includes image information and integratedinformation; and identifying the image sensor based on analysis of thedata, wherein the image information is obtained by an analog/digitalconversion device of the image sensor.